How are deleted scalar fields (e.g. `version`) represented in the "diff" data

e.g. the following approved item has "NEW" as the value for the version field:

curl "https://sshoc-marketplace-api.acdh-dev.oeaw.ac.at/api/tools-services/DHcf5z"

there is also a suggested version of that item, which has the version field removed:

curl "https://sshoc-marketplace-api.acdh-dev.oeaw.ac.at/api/tools-services/DHcf5z/versions/63912" -H "authorization: ${SSHOC_TOKEN}"

when querying the diff:

curl "https://sshoc-marketplace-api.acdh-dev.oeaw.ac.at/api/tools-services/DHcf5z/diff?with=DHcf5z&otherVersionId=63912" -H "authorization: ${SSHOC_TOKEN}"

the version field is omitted in result.other. it is currently unclear if this signifies that the field has been deleted, or that is is unchanged?

for comparison, this suggested version did not change the version field (the value is still "NEW"), however, here version is also omitted from the diff response:

curl "https://sshoc-marketplace-api.acdh-dev.oeaw.ac.at/api/tools-services/DHcf5z/diff?with=DHcf5z&otherVersionId=63913" -H "authorization: ${SSHOC_TOKEN}"